Underwater propulsion device for swimmers



Dec. 26, 1961 w. J. FOGARTY ETAL 3,014,448

UNDERWATER PROPULSION DEVICE FOR SWIMMERS Filed April 21, 1959 WILFQED J. FoeAlz'rv WARNER 6.5.MILLEI2 HARRY 1.. FOOD I2ICHAQD FRIEDMAN IN V EN TORS BY M IMM ATTORNEYS United States This invention relates to underwater propulsion devices for use by swimmers and particularly by skin divers; and has as an object the provision of a compact device of this character arranged to be strapped to the back of a swimmers body and includes novel means for securing the conventional air tanks to the propulsion device.

A further object is to provide a device of this character which utilizes a novel sealed unit containing power and driving elements mounted and assembled in a novel manner.

A still further object is to provide a device of this character employing novel means for improving the thrust produced by the propeller element.

Additional more subordinate objects'and advantages will appear hereinafter.

While we shall point out in the appended claims the features which we believe to be new, we shall now, for the purpose of enabling those skilled in the art to make and use apparatus embodying our invention, describe a presently preferred embodiment thereof. We wish to point out, however, that various modifications and rearrangement of parts may be made without departing from the broader scopeof the invention as defined by the claims. I The accompanying drawing illustratessaid. presently preferred embodiment of our invention and, in that drawing;

FIG. 1 is a view taken on line 1-1 of FIG. 2, partly in longitudinal section and partly in side elevation, showing our device strapped to the back of a swimmer;

FIG. 2 is a top plan view; and

FIG. 3 is a section taken on line 3-3 of FIG. 2.

Referring now to the drawing the letter S denotes the body of a swimmer, on the back of which is attached, by means of a suitable harness 5, an elongated hollow casing 6 having a side wall 7, and having a top wall 8 presenting rectangular access openings 9, 10 normally closed and sealed by cover members 11 secured to the casing as by screws 11a. A partition wall 15 separates the interior of the casing into a forward compartment 17 and a rear compartment 18, the partition wall having a transverse opening 20 preferably lined by a bushing 21. I

The casing has a rear end wall having an opening 26 therethrough lined by a bushing 27 for journaling the propeller shaft to be described.

Within the forward compartment 17 I mount an electrical power source such as a plurality of conventional storage batteries B suported from the bottom wall of the casing by supporting blocks 30. Wires 32 conduct the electricity from the batteries, through a conventional D.C.-A.C.-D.C. converter 33, to a motor mounted in the rear compartment 18, the wires passing through the ,bushing 21 which lines the opening 20 in the partition wall.

The motor shaft 35 is connected to a propeller shaft 38 by a flexible joint 36 from which the propeller shaft passes through bushing 27 in which it is journaled, and projects from the rear end of the housing, having a screw type propeller 39 secured on its projecting end portion. A spacer sleeve 40 is interposed between the rear end wall 25 and the motor in spaced relation to the joint 36.

* atentO swimmer.

ice

relationship to the outer surface of the casing by circumferentially spaced webs or blocks 47 so as to provide an annular water passageway 48. The inner diameter of the guard decreases towards its rear end causing the propeller to produce a rearwardly directed jet stream of improved thrust.

A control switch 50 is connected, by a cable 51, into the motor, the switch being preferably secured to the harness portion 5a which extends over the shoulders of the The harness 5 has a fastening element 53 to secure its free ends together about the body of the swimmer, the harness being also secured in any suitable manner to the bottom of the casing.

As best shown in FIG. 3, there is a concaved recess 55 in each of the opposite sides of the casing to conform to and receive a pair of conventional air tanks 57. To retain each of said tanksin its said recess, I secure in each recess the inner ends of a pair of straps 60, the outer ends of the straps of each pair being secured together as by a conventional buckle 62.

Preferably I adhere to the bottom exterior surface of the'casing a resilient pad 65, such as of sponge rubber, which will substantially conform to the contour of the swimmers back when the casing is secured on the swimmer by the harness.

The outlet ends 57a of the air tanks 57 are connected into a common conduit 58 which is closed at its ends. Between the ends of the conduit there is an outlet 67 controlled by a valve 68, to which outlet a conventional flexible hose may be connected to carry air to a conventional swimmers helmet, not shown, worn by the swimmer. I

A connection element 70 extends through a correspond ing opening in the front end wall 6 of the casing, by

means of which a conventional battery recharger may be connected to the batteries B when the device is not in use. When not in use, the connection element 70 is covered by a friction fitting cap 71.

In operation, when the device is secured on the back of the swimmers body by the harness the swimmer is submerged and he may manually control the switch 50 to energize the motor which drives the propeller, to propel the swimmer through the water. The described means by which the air tanks'57 are secured in the concaved recesses 55 renders unnecessary any separate harness for the tanks and insures that the casing 6 and the air tanks remain assembled as a unit. To service any of the components mounted inside the casing, either or both of the covers 11 may be removed and reinstalled after the servicing is efiected. I

We claim:

1. In a device for propelling a submerged swimmer through water, a hollow casing having a rearwardly tapering rear end portion-of round cross section and having a longitudinally extending channellike, outwardly opening recess in each of its opposite sides, a pair of air tanks, means releasably securing said respective tanks in said respective recesses, a power driven propeller shaft extending axially from the rear end of said casing, a prm peller on said shaft, a rearwardly tapering annular guard member mounted on the rear end portion of said casing in spaced surrounding relationship thereto whereby to provide an annular waterpassage way. therebetween, said guard member surrounding said propeller, and a harness secured to and depending from said casing whereby to provide means for attaching said casing to the back of a submerged swimmer. 5

2. The 'device of claim 1 which additionally includes means extending transversely of the front end of said casing and securing said tanks together.

3. The device of claim 1 which additionally includes a soft rubber-like pad carried by the bottom surface of 1 said casing.

References Cited -in the file of this patent UNITED STATES PATENTS Edwards Mar. 10, 1942 Keogh-Dwyer Nov. 1, 1955 Krieghofi Nov. 1, 1955 FOREIGN PATENTS Germany July 22, 1953 France June 24, 1957 

